Pneumatic transport systems are well-known for the transport of pneumatic transportable material between, for example, a first origin location and a second destination location in a plurality of interconnected tubes. A typical pneumatic transport system includes a number of pneumatic tubes interconnected to a conveying line such as a pipe-line to transport pneumatically transportable material therein. Various pneumatic transport devices, at the first location, the origin and/or the second location, the destination, provide a force affecting a fluid, such as air, flowing in the pipe-line for transport of the pneumatic transportable material within the pipeline. Thus, the pneumatic transport system transports material under fluid pressure or vacuum. Often vacuum is used in these pneumatic transport systems and they are therefore sometimes simply referred to as “vacuum conveying technology”.
The pneumatic tubes forming the conveying line of the pneumatic tube transport system for instance using vacuum conveying technology may be arranged in any manner that allows the material to be transported between various locations including straight tubes but also bent tubes. It will be appreciated that the distances between origin and destination locations in the pipeline may be quite large and that a material transport speed may be quite high within the pipe-line.
The pneumatic transport systems are also typically required to handle a large variety of products from bridging to free flowing powder.
Typical applications of pneumatic transport systems, in particular conveyor lines, using vacuum technology, i. e. vacuum conveying technology are food and pharmaceutical industries, requiring “robustness” among other requirements.
By the term “robustness” is meant herein that the pneumatic transport system has to be able to transport the material at a reasonable high speed without destroying the material, which is often fragile and may be damaged during transport. For instance, if the speed of transport of the material is high, or “too” high, and the material hits a tube bend, or parts of the material collides with itself, for instance tablets colliding with each other during transport within the pipe-line, the material may be destroyed. Thus, a “too” high speed of transport, such that material is destroyed is not desirable.
If “too” much material is feed into the pneumatic tube transport system, as regards transport capacity of that particular pneumatic transport system and the properties of the material to be transported, the speed of transport of material will decrease, and thereby also transport capacity.
There are also other problems with too high speed of transport resulting in unnecessary high wear of tubes or other components used in the transport system.
There are also problems with expensive electronic control systems requiring expensive types of sensors, such as speed detection sensors. An example of a system using speed detection sensors is disclosed in EP 2 003 075 A1. The sensors are located in the transport path.
Until now, none of these problems related to pneumatic tube transport systems have been fully addressed according to our knowledge.